Al-Isra' - ১৭:৩২

وَلاَ تَقْرَبُواْ الزِّنَى إِنَّهُ كَانَ فَاحِشَةً وَسَاء سَبِيلاً
And go not nigh to fornication; surely it is an indecency and an evil way.
Nor come nigh to adultery: for it is a shameful (deed) and an evil, opening the road (to other evils).
And come not near unto adultery. Lo! it is an abomination and an evil way.